•Rape (sibling rape)
•Other minor mental health issues (anxiety and things of that nature)
If any of these topics trigger you or you just don't like to read about them there will be a warning at the beginning of every chapter covering these topics. I would recommend not reading the book at all if these topics are sensitive for you because one of the main plots in this story involves one of those points.
These concepts start getting brought up a little later in the book, not right away, probably about chapter 7 is when it is first mentioned briefly. There is a brief mention of them in earlier chapters but the first real conversation happens around chapter 7-10